More Java things from K-State: LTI Launch and Attendance tool

Community Member

Kansas State University is proud to announce our first open source LTI application. It is an attendance taking tool. The source code is available on GitHub.

Previously we released a Java library to interface with the Canvas API. (blog post | code) This API library is now being used by a couple other universities and we have received several pull requests to add more functionality. Thank you to the Canvas community for embracing open source software and contributing back! We hope that this will continue.

Now, as part of the attendance taking application, there are a few other bits we would like to highlight. All of our LTI applications are based on an LTI launch framework to handle common launch tasks and provide common resources. We hope that others may find it useful in implementing their own LTI applications. In order to assist in learning how to use it, we have created a minimal self-contained LTI application that shows how to use the launch framework. Here are some details on these parts:

Attendance LTI application

This application was developed before Instructure released the Roll Call application as open source so it may not be quite as valuable now but it may still be worth a look if there is functionality you are missing in the existing Canvas experience.

Initially, we developed this application for the K-State Polytechnic Campus in Salina, Kanas. Their aviation maintenance program has strict guidelines from the FAA, which requires them to track contact time between students and instructors down to the minute. Later, we extended the application to be more broadly useful to the campus community.

Some of the features of the application include:

  • Minute versus daily attendance tracking, configurable by the instructor on a per-course basis
  • Instructors can choose to allow or prohibit students from seeing details of their attendance records
  • Attendance can be pushed to the Canvas grade book as an assignment

There is still some room for improvement to make this application more useful to other institutions. Depending on your existing environment, here are some specific hurdles you may face when trying to deploy this application:

  • The application was written against an Oracle database. It should not take too much effort to make the application database agnostic since we use Hibernate. We may get around to this at some point to allow for better testing.
  • We tried to avoid using K-State specific terms and branding but some did slip in. For example our SIS ID is commonly called the "Wildcat ID" and shows up as "WID" in some parts of the application.
  • The deployment process is not exactly simple. It would be great to have a docker image that packages the application and container together for easy deployment. Currently it runs on Wildfly. There is an file in the repository that details every step needed to install the application in a UNIX-like environment.

LTI Launch Framework

This framework is based on Spring and handles LTI launch requests. (source code: GitHub) Spring Security is used to handle verifying the OAuth signature that comes with the LTI launch request. It also assists your application in getting an API access token from the user via the OAuth2 flow.

Because this framework is based on Spring, you must implement some interfaces and make the implementations available as Spring beans. These beans handle persisting user OAuth tokens for subsequent application launches, generally setting up the LTI application, and ensuring that the application is communicating with the correct Canvas instance. The last part is vital for hosted Canvas customers because it prevents a test version of the application from accidentally interacting with a production instance of Canvas. This mixup can readily occur when the test environment gets automatically overwritten with production settings periodically.

We have run into challenges as it relates to error handling in Spring. At the moment it is left mostly up to your application to handle specific errors correctly. This leads to some code duplication for handling common LTI related error conditions. As time permits, we are working to improve this problem.

Minimal LTI application

We created a minimal LTI application to demonstrate how to use the LTI Launch Framework. (source code: GitHub) The application outputs a simple page of text. It only authenticates the LTI launch request and then echoes back information including the username and LTI parameters being used in the application.

Unlike the Attendance application, this one is trivial to deploy! It uses maven to build an executable JAR which contains an embedded Tomcat server. Running it as as simple as executing the command: java -jar lti-launch-example.jar

Comments (and pull requests) are welcome!

Tags (2)
1 Comment